It is a hardware problem, confirmed by several sources. Basically rub the screen diagonally for a few seconds and the screen will stop responding any touches, but it recovers after a few seconds.

Samsung can probably put this in its next commercials, saying the Galaxy has bug free touch screen.

Quote:

First noticed by game developer CMA Megacorp, the iPhone 5 appears to react differently than previous generations of the device when sliding a finger diagonally across the screen in quick succession. The average user might not notice the glitch, but the issue could be a problem for game developers that rely on quick diagonal scrolling and swiping motions. As highlighted by Recombu in the video above, “the problem is exacerbated by scrolling diagonally and as you can see only occurs on the iPhone 5.” In the video, we see the theory put to the test on two iPhone 4Ss and two iPhone 5s, one of each running iOS 6.0 and 6.0.1, indicating the issue might indeed be hardware related.